Low birth weight ups IBS rate, say authors

People with a birth weight lower than 2.5kg (5.5lb) are at a greater risk of developing IBS than heavier babies, say Norwegian researchers.

People with a birth weight lower than 2.5kg (5.5lb) are at a greater risk of developing IBS than heavier babies, say Norwegian researchers. The team based their findings on 3,334 twin pairs, 1,250 of whom were identical. The twins completed a comprehensive questionnaire about their health, including whether, and when, they had ever had IBS. This information was then matched with weight at birth, supplied by the national twin registry and divided into four groups, ranging from less than 1,500g to more than 2,500g. A healthy birth rate was deemed to be 2.5kg. The researchers found that those born weighing less than 2.5kg were more likely to have had IBS - although they were unable to quantify the exact size of the effect. For those born weighing less than 1.5kg, the difference was more marked: they were 2.5 times more likely to have had IBS when compared with those weighing above 2.5kg. Lead researcher Dr May-Bente Bengston, of the University of Oslo, said this was a “significantly higher risk”, adding that several chronic diseases have been linked to low birthweight, and that the healthy development of the digestive system, which is not complete at birth, could be hindered by insufficient fetal growth. The team also found that the twins with the low birth weight were more likely to develop IBS about eight years earlier than those weighing over 1.5kg. The rate of IBS across the entire sample was 5.4%, roughly one in 20. But there was a significant gender difference: the rate in men was 3%, while that in women was 7%. The likelihood of IBS was also stronger among the identical twins, suggesting that genetic factors do play a part. Dr John de Caestecker, a gastroenterologist from Leicester General Hospital, said: “There is a lot of interest in chronic pain syndromes on the effect of early life experiences on the pain pathways. “Experimental models have shown that stressing animals in the neonatal period can alter their pain sensitivity later in life. “One just wonders whether the lower birth weight babies are more stressed babies and this affects their susceptibility to IBS.”